This depends very much on the kind of antidepressant medication. Usually it is not a good idea to stop at once because mild to severe withdrawl symptoms might occur (especially with SSRI). You should try to get medication again. I am aware of some programs for patients with financial problems in the US (but I am working in Germany). Some pharmacocompanies offer the medication for free for a special group of patients. Try to talk to a doctor about this problem.